June 16, 2025 • 18 mins
🧑⚕️ FREE MSRA PODCAST – Adult Seborrhoeic Dermatitis: High-Yield Revision
🎯 Everything you need to revise seborrhoeic dermatitis in adults for the MSRA. Cut through the noise—covering causes, clinical features, management, differentials, and more.
Key Learning Points
🔍 Definition
• Seborrhoeic dermatitis is a chronic, relapsing inflammatory skin disorder affecting oily areas—scalp, face, chest
• Linked to the yeast Malassezia; not contagious
💡 Causes & Risk Factors
• Overgrowth or sensitivity to Malassezia yeast
• Sebaceous gland activity (oily skin)
• Family history, stress, immunosuppression (HIV, Parkinson’s), winter, hormonal changes
• Aggravated by illness, fatigue, medications
🧬 Pathophysiology
• Overreaction of immune system to Malassezia yeast on sebum-rich skin
• Inflammation → increased turnover → greasy yellow scales, redness, itch
🩺 Clinical Features
• Greasy, yellowish scales over red, itchy patches
• Affects scalp (dandruff), eyebrows, nasolabial folds, central face, chest, upper back, flexures
• Worse in winter; flares/remissions
• Often chronic but manageable
📝 Differential Diagnosis
• Psoriasis (thick, silvery scales, extensor surfaces)
• Atopic dermatitis, contact dermatitis, tinea capitis/versicolor, rosacea, lupus, candidiasis
🔬 Diagnosis
• Clinical—based on typical rash and distribution
• Fungal scrapings or biopsy only if diagnosis is unclear
💊 Management
• Topical antifungals: ketoconazole, ciclopirox (creams, shampoos)
• Topical corticosteroids for flares (short term only, low-potency for face)
• Maintenance with antifungal shampoos
• Calcineurin inhibitors (tacrolimus, pimecrolimus) as steroid-sparing options
• Severe/atypical cases: screen for HIV
• Rare: systemic antifungals, oral tetracyclines, isotretinoin
📈 Prognosis
• Chronic, relapsing-remitting; no cure but usually controllable
• Significant impact on quality of life, but rarely causes serious complications
• Risk of secondary infection if scratched/broken skin
📎 More MSRA Revision for Seborrhoeic Dermatitis in Adults:
📝 Revision Notes: https://www.passthemsra.com/topic/seborrhoeic-dermatitis-in-adults-revision-notes/
💬 Flashcards: https://www.passthemsra.com/topic/seborrhoeic-dermatitis-in-adults-flashcards/
🧠 Accordion Q&A: https://www.passthemsra.com/topic/seborrhoeic-dermatitis-in-adults-accordion-qa-notes/
🚀 Rapid Quiz: https://www.passthemsra.com/topic/seborrhoeic-dermatitis-in-adults-rapid-quiz/
🧪 Full Quiz: https://www.passthemsra.com/quizzes/seborrhoeic-dermatitis-in-adults/
🎓 Dermatology Course: https://www.passthemsra.com/courses/dermatology-for-the-msra/
🌐 For more free & premium revision resources:
https://www.passthemsra.com
#MSRA #SeborrhoeicDermatitis #MSRARevision #PassTheMSRA #FreeMSRA #Dermatology #MSRAFlashcards #MSRATextbook #MSRAQuiz #Sca
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Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
(00:00):
Welcome to the Deep dive. Today we're diving into a topic
that's really common, maybe morecommon than you think, and
definitely important, especiallyif you're prepping for something
like the MSRA exam. Yeah, absolutely.
Going deep on adult seboroic dermatitis.
And we've got some really high yield focused info lined up.
Think of this as your essential revision guide, but you know, in
(00:23):
audio form. Exactly.
Our mission today is basically to cut through the noise, give
you the absolute key facts aboutsaberuic dermatitis in adults.
So what it is? Why it happened?
What it looks like, how you manage it, right?
All that stuff, it's really about getting those core details
to stick, whether it's for an exam or just so you're properly
informed. OK, so let's just jump right in
(00:43):
then. At its most basic, what exactly
is adult zebraic dermatitis? Well.
At its core, it's a really common chronic inflammatory skin
condition. Chronic meaning it sticks
around. It's not a one.
Off exactly, that's key. It tends to have periods where
it gets better than worse again,and it specifically effects
areas of skin with lots of sebaceous glands.
(01:05):
The oil glands? Yep.
So think the scalp, the face, the chest, sometimes the upper
back too. And what does it actually look
like? What would you see?
OK, the hallmark is red, scaly itchy patches, but the type of
scale is really characteristic. It's usually described as like
greasy or maybe yellowish scaleson top of that redness.
(01:26):
Greasy scales, OK. And it's really important to
remember it's not contagious. You can't catch it from someone.
Right, that's good to know. Now I've heard it's often linked
to a specific yeast malicetzia. Tell us about that connection.
Yeah, that's right, Malicetzia ferfer yeast.
You might also see it called Pityrus sporum Oval.
It's strongly implicated. Implicated how?
(01:47):
Well, the exact cause isn't fully nailed down, but the
thinking is that an inflammatoryreaction in the skin to this
yeast may be an overgrowth, or just how the body reacts to it
plays a really big role. So the yeast itself isn't the
problem, it's the reaction. Pretty much.
It's considered a benign scalingrash, usually starting sometime
after puberty. OK, so if the exact cause is a
(02:08):
bit of a puzzle, what do we knowcontributes?
What are the big factors? It's definitely multifactorial,
not just one single thing. So yes, you've got the
malicetia, yeast overgrowth or sensitivity.
Then there's an abnormal immune response in people who are
susceptible. Genetics probably plays a part.
Runs in families sometimes. Can do, And the activity of
(02:29):
those sebaceous glands is crucial too, because that's the
environment the yeast likes. So it's kind of a mix of things
coming together. Exactly.
Your body mounts this inflammatory response to the
yeast in those oily areas, and that's what leads to the skin
changes we see. It seems like some people's
immune systems just overreact tothis really common yeast.
(02:50):
What about things that make it worse, like triggers?
Yeah, definitely. Things can aggravate it.
Stuff like being I'll stress is a big one.
Fatigue. Stress.
Always stress. Tell me about it.
Seasonal changes too, often, worse in winter.
Having a weakened immune system for any reason, even some
medications, can trigger it. And we also see it more often
(03:12):
and sometimes more severely in people with certain neurological
conditions. Parkinson's disease is the
classic example. And Parkinson's, well, the
thinking is that immobility might contribute to sebum sort
of building up, making it a better environment for the
yeast. Interesting.
And dandruff? Where does that fit in?
Is it just mild sebroeic dermatitis?
(03:32):
Pretty much yeah. Dandruff or pitiosicopitis is
basically considered a non inflamed form just on the scalp.
You get the scaling but usually not that significant redness you
see in full blown sebroeic dermatitis.
So related, but less severe. Exactly right.
Who's more likely to get this then?
Are there specific risk factors we should know about?
(03:52):
Definitely. There are known risk factors.
So having a family history bumpsup your chances.
Makes sense having oily skin, which is logical given where it
pops up. Yeah.
And then certain medical conditions really increase the
risk. Yeah, we mentioned Parkinson's.
And HIV. Yes, HIV is a big one.
The rates are much, much higher in people with HIV.
Yeah. And it can be more severe, too.
Yeah, that's a really key association to remember.
(04:14):
OK, HIV, Parkinson's. What else?
Stress. Definitely a risk factor and a
trigger and generally having a weakened immune system from any
cause. In age you mentioned it starts
after puberty. Yeah, it has this interesting
pattern. It's really common in babies.
That's cradle cap. Then it can peak in adolescence,
and then there's another major peak in adults, typically
(04:35):
between 30 and 60 years old. Got it.
Infants, teens, and middle-aged adults.
That's the pattern. OK, let's dig a bit deeper into
the pathophysiology. What's actually happening sort
of under the skin? Right.
So it really comes down to that interaction we touched on.
He's got the malicids, the yeasts which live normally on
(04:55):
most people's skin. They feed on the oils, the sebum
produced by those sebaceous glands.
Now in someone who's susceptible, their immune system
seems to recognise bits of this yeast or stuff it produces and
kicks off an inflammatory response.
Like an overreaction, you said. Exactly like an exaggerated
response. And that inflammation is what
causes the skin cells to turn over faster, leading to the
(05:18):
scaling, and it also causes the redness and the itch.
And the link to HIV and Parkinson's, how does that fit
pathophysiologically? Well, it likely relates to how
those conditions affect either the immune system.
Like with HIV the immune regulation is off or maybe sebum
production or it's composition like potentially in Parkinson's.
(05:38):
It just makes individuals more prone to this inflammatory
reaction. OK, that makes sense.
So we've got this picture, red, greasy, scaly patches,
especially in those oily zones. But you know, lots of skin
conditions can look kind of likethat.
Absolutely. So for revision, knowing what
else it could be, the differentials, that's super
(05:59):
important, is it? Oh definitely, this is a key
area. While you know often you can
diagnose Sebra dermatitis just by looking, especially in a
typical case, you have to consider other possibilities,
especially for exams. So what are the main ones?
The big ones that can look similar are psoriasis, atopic
dermatitis that's eczema, contact dermatitis and various
fungal infections like ringworm.Right.
(06:21):
How do you start to tell them apart?
Thinking about the location is really helpful, just like you
would in clinic. OK, give us some examples, say
on the face. OK, on the face, besides
seborroic dermatitis, you might think about rosacea.
That usually involves redness and flushing, maybe some spots,
but typically doesn't have that prominent greasy scale.
Or even something like lupus, which can cause a facial rash,
(06:42):
though that's often more triggered by the sun.
And the scalp, that's a common spot.
Yeah, the scalp is key. Psoriasis is probably the number
one differential there, and sometimes they can even overlap,
which gets confusingly called C bump psoriasis.
How scalp psoriasis different? Typically psoriasis scales are
thicker, drier, and more silverywhite compared to the greasy,
often yellowish scales of Subderm.
(07:05):
Psoriasis also often affects theelbows, knees, lower back places
Subderm usually doesn't. OK, thicker silver scales.
Think psoriasis. What else on the scalp?
You'd also think about maybe infected eczema or teenicopedus.
That's fungal ringworm of the scalp, right?
And on the torso, chest and back.
Yeah, the list gets a bit longer.
There could be a topic, eczema, often drier and maybe different
(07:28):
spots like elbow creases could be contact dermatitis if it's
localised where something touch the skin.
OK, maybe pityriasis rosea, which has quite a distinct
Harold patch and Christmas tree pattern, Usually pityriasis
versicolor, another fungal thing, often causing pale or
dark patches on the back and chest like in simplex, which is
thickened itchy skin from chronic scratching or
(07:49):
Candidiasis, a yeast infection often in skin folds.
Wow, OK, that's quite a list forthe torso.
So the key is really looking closely at the type of scale and
the exact location. Exactly combine the location
those classic sebaceous gland areas like scalp, eyebrows,
nasolabial folds, chest with thequality of the rash.
Remember red bass? Greasy or yellowish scales?
(08:12):
That's your classic Subderm picture.
So let's try a mini vignette like for revision.
Say a 45 year old man comes in itchy scalp for months, greasy
yellowish scales, also got some redness and flaking around his
nose and in his eyebrows. Most likely diagnosis.
Bingo. Greasy yellow scales on the
scalp plus facial involvement inthose classic spots in as labial
fold eyebrows. That pattern shuts seborrheic
(08:33):
dermatitis. But if the vignette said thick
silvery scales on the scalp and patches on his elbows.
Then you'd be leaning much more towards psoriasis.
See how the details matter. Got it.
Greasy plus typical location. Likely Subderm.
OK, let's talk numbers. How common is this globally?
UK. It's really pretty common.
Generally, sources say it affects somewhere between maybe
(08:55):
1 to 5% of the global population.
Some figures put it around 2% overall.
OK. But as we keep saying, the big
headline in epidemiology is thathuge difference in people who
are immunocompromised. Right, the HIV link.
Exactly. And people with HIV, the
prevalence just rockets up figures like 34% to even over
80% are quoted, and it tends to be more widespread and severe,
(09:17):
especially with advanced HIV or AIDS.
That's a critical link. Any difference between men and
women? Yes, generally it's more common
in males. Why is that?
The thinking is it might be linked to male hormones,
androgens, influencing the sebaceous glands to produce more
oil, creating that favourable environment.
OK. And just to recap those age
peaks again. Yep.
Infant's cradle cap, then adolescence, and then that big
(09:39):
adult peak, usually 30s to 60s. Right.
We've touched on the general look, but let's get really
specific about the clinical features.
How does it present in those different areas?
OK, let's break it down again. Always thinking red base, greasy
yellowish scale. Location is everything on the
face. Classic spots are the nozolabial
(10:01):
cake folds, those lines from nose to mouth, over the bridge
of the nose, in the eyebrows, the central forehead, even the
eyelashes. That's called cibroic
blepharitis. It looks like inflamed, maybe
slightly greasy patches with fine scales.
And the scalp. Scalp is probably the most
common sight. It can range from just simple
dandruffine, white scaling to more obvious I'll defined.
(10:23):
Pink patches with thicker yellowish or white scale can
affect just part of the scalp orthe whole thing.
Itch is really common. Here, Yeah, itchy scalp sounds
miserable. What about chest and back?
On the chest and upper back you might see small sort of reddish
brown bumps with greasy scales off and around hair follicles.
Or you can get larger, more defined patches.
The area right over the sternum,the breastbone is a really
(10:44):
classic spot. OK, sternum, good tip and
flexures like armpits. Yeah, the in the Fletcher's
armpits, groyne area, under the breasts, sometimes behind the
ears. It tends to present as just red
patches, maybe some bumps or plaques because it's in a fold,
might look a bit moist and can sometimes resemble interfrigo,
which is just irritation from skin rubbing on skin.
(11:05):
So the appearance can vary a bitdepending on the location, but
that greasy scale and redness and oily areas is the theme.
Exactly. Now, how do doctors actually
diagnose this? Do you need lots of tests?
Well, good news here. For exams and practise,
diagnosis is usually pretty straightforward.
Most of the time it's a clinicaldiagnosis.
Meaning you just look at it. Take a history.
(11:27):
Yep. Based on the characteristic
appearance that rash we described and where it is on the
body, plus the patient's story, the itch, any triggers they've
noticed if it comes and goes. So usually no blood tests or
biopsies needed. Not routinely, no.
Specific investigations aren't typically required if the
pitcher looks typical. When might you do a test then?
(11:47):
Really only if the diagnosis is uncertain or if you're actively
trying to rule out one of those differentials we talked about.
Like the fungal? Infection.
Exactly, If you suspect teeny capitis on the scalp or maybe
Peter Isis versicolor on the chest, you might do a skin
scraping. You scrape off a few scales,
send them for microscopy and culture to look for fungus.
And a biopsy. Very rarely, maybe if it looks
(12:09):
really unusual or isn't responding to standard
treatments and you're still scratching your head about the
diagnosis after considering the common stuff.
OK. So mostly clinical diagnosis,
once it is diagnosed, how do we treat it?
What are the main goals right the.
Goals are pretty clear. We want to one, control the
symptoms like the itch and scaling, 2.
Reduce the inflammation and redness and three, basically
(12:31):
clear up the rash during those flare ups.
And topical treatment stuff you put directly on the skin are
absolutely the mainstay. Creams, shampoos, lotions.
What kinds of ingredients are inthese topicals?
2 main types. First, topical antifungals.
Things like ketoconazole or cyclopyrox.
These target that malicets the yeast.
OK, tackling the yeast. And 2nd topical corticosteroids.
(12:54):
These are anti inflammatories. They calm down the redness and
the itch. Usually used just for short
periods during a flare. What about specifically for the
scalp? Any particular approach?
Yeah, there's often a stepwise approach recommended, like in
the nice CKS guidance. You might start with over the
counter shampoos containing things like zinc pyridione.
Like head and shoulders. Exactly, or Coltar shampoos.
(13:17):
If those aren't cutting it then you step up to medicated
shampoos like ketoconazole shampoo may be used a couple of
times a week. Selenium sulphide shampoo is
another option, and you can alsoget topical steroid lotions or
gels specifically for the scalp if the inflammation is bad.
OK. And for the face and body,
similar idea. Similar principle, yeah, topical
antifungal creams like ketoconazole cream and again,
(13:39):
topical steroids, but usually milder ones on the face.
Use sparingly and for short bursts to manage flares.
You mentioned it's chronic so flares are common.
How do you manage that long term?
That's the challenge. Because recurrences are so
common, treatment often involvesnot just treating flares when
they happen, but sometimes usingtreatments regularly to prevent
them. Like maintenance therapy?
(14:00):
Exactly. Yeah, maybe using an antifungal
shampoo once or twice a week, even when the scalp is clear, or
intermittent use of the topical steroid if needed.
The combination of regular antifungal use with intermittent
steroids is a common strategy. Any other options?
Yeah, another class of topicals sometimes used, especially on
the face where you want to avoidtoo much steroid, are
(14:22):
calcineurin inhibitors, things like tacrolimus or PIE
macrolimus. They also reduce inflammation,
but work differently from steroids.
They're increasingly seen as a good alternative or addition.
OK, what if it's really severe, like widespread or just not
responding to topicals? For those more severe or
resistant cases, you might have to consider systemic treatments
(14:42):
pills. Oral antifungals like
ketoconazole tablets can be used.
Sometimes oral antibiotics like tetracyclines are used not
really for infection but for their anti-inflammatory effects.
And then in really difficult rare cases, things like oral
isocretinoline, you know, the strong acne drug or even
ultraviolet light therapy might be considered.
But these are definitely specialist treatments.
(15:03):
And you mentioned that link again if it's severe or
atypical. Yes, absolutely.
Crucial point, especially for exams.
Severe, widespread or atypical cibroic dermatitis.
You must consider testing for underlying HIV infection.
That association is just so strong.
Got it. OK.
Moving towards the long term outlook, what's the prognosis
(15:25):
generally like? Well, like we said right at the
start, it is a chronic condition, so unfortunately
doesn't typically just vanish forever on its own.
So no cure. No complete cure.
As such, what people can expect is a course that waxes and
wanes, periods where it flares up, the rash is active, and
periods of remission where it clears up or is much quieter.
But it is manageable. Yes, that's the good news.
(15:45):
While there's no cure, it usually responds well to the
treatments we've discussed. Effective symptom management is
definitely achievable for most people, but you have to
anticipate those relapses. They're just part of the deal.
Managing expectations is important, OK.
And does it lead to any serious complications, usually anything
dangerous? Generally speaking, no.
(16:08):
The sources usually say there aren't typically serious
physical health complications directly from the subderm
itself. But it can affect quality of
life. Oh absolutely, the itch can be
really bothersome sometimes, burning sensations, and because
it's often visible face scalps, it can definitely have a
significant impact on quality oflife, cause emotional distress,
(16:29):
affect self esteem. We shouldn't underestimate that.
Any risk of infection? Yes, there's a risk of secondary
bacterial or fungal infection developing on the inflamed skin,
especially if it gets scratched a lot and the skin barrier is
broken. And then very rarely in really
severe cases, again often linkedto things like immunosuppression
or maybe severe heart failure, it could potentially progress to
(16:50):
cover most of the body surface with redness and scaling.
That's called generalised sybaric erythroderma, but that's
quite uncommon. Wow, OK, that was a really
comprehensive run through of adult Saberac dermatitis.
We've covered well everything from the potential causes that
malicets ease the immune response to what it actually
looks like, those greasy scales and specific spots.
(17:13):
Yeah, and how to tell it apart from other things like
psoriasis, which is key. Definitely.
And the management that stepwiseapproach focusing on topicals
first. Absolutely understanding those
core features, greasy scale location, malacetzia link, those
HIV Parkinson's associations. That's gold dust for recall,
especially in an exam. And I think knowing it's chronic
(17:33):
but manageable, that treatment is about controlling flares,
maybe some maintenance. That's a really important take
home message. Totally agree, and remembering
diagnosis is usually clinical. That saves unnecessary tests.
It's common, so you'll definitely see it being
comfortable recognising it and knowing those first steps is
super useful. So what does this all boil down
(17:54):
to for you? Listening.
Hopefully a much clearer, more structured picture of adult
seborrheic dermatitis. Remember the key takeaways,
greasy scales, those typical locations, scalp, face, chest,
the malesedia connection and think about those associated
conditions like HIV and Parkinson's, especially in
severe cases. And keep those main
(18:14):
differentials, especially psoriasis in the back of your
mind when you see a scaly scalp.Knowing the typical treatments,
antifungals, short term steroidsand that clinical diagnosis
rule, those are really high yield points.
OK, a final thought to leave youwith then.
Given how closely this seems tied to malicidia, yeast and the
individual's immune reaction, what might future research look
like? Could we see maybe more targeted
(18:36):
treatments, perhaps something that deals with the use more
specifically? Or fine tunes just that bit of
the immune response without knocking the whole system?
Something to think about. For more free MSRA revision
resources, do visit freem-sra.com and IF if you're
looking for the full premium Revision toolkit, head over to
athmsracom.
Welcome to the Deep dive. Today we're diving into a topic
that's really common, maybe morecommon than you think, and
definitely important, especiallyif you're prepping for something
like the MSRA exam. Yeah, absolutely.
Going deep on adult seboroic dermatitis.
And we've got some really high yield focused info lined up.
Think of this as your essential revision guide, but you know, in
(00:23):
audio form. Exactly.
Our mission today is basically to cut through the noise, give
you the absolute key facts aboutsaberuic dermatitis in adults.
So what it is? Why it happened?
What it looks like, how you manage it, right?
All that stuff, it's really about getting those core details
to stick, whether it's for an exam or just so you're properly
informed. OK, so let's just jump right in
(00:43):
then. At its most basic, what exactly
is adult zebraic dermatitis? Well.
At its core, it's a really common chronic inflammatory skin
condition. Chronic meaning it sticks
around. It's not a one.
Off exactly, that's key. It tends to have periods where
it gets better than worse again,and it specifically effects
areas of skin with lots of sebaceous glands.
(01:05):
The oil glands? Yep.
So think the scalp, the face, the chest, sometimes the upper
back too. And what does it actually look
like? What would you see?
OK, the hallmark is red, scaly itchy patches, but the type of
scale is really characteristic. It's usually described as like
greasy or maybe yellowish scaleson top of that redness.
(01:26):
Greasy scales, OK. And it's really important to
remember it's not contagious. You can't catch it from someone.
Right, that's good to know. Now I've heard it's often linked
to a specific yeast malicetzia. Tell us about that connection.
Yeah, that's right, Malicetzia ferfer yeast.
You might also see it called Pityrus sporum Oval.
It's strongly implicated. Implicated how?
(01:47):
Well, the exact cause isn't fully nailed down, but the
thinking is that an inflammatoryreaction in the skin to this
yeast may be an overgrowth, or just how the body reacts to it
plays a really big role. So the yeast itself isn't the
problem, it's the reaction. Pretty much.
It's considered a benign scalingrash, usually starting sometime
after puberty. OK, so if the exact cause is a
(02:08):
bit of a puzzle, what do we knowcontributes?
What are the big factors? It's definitely multifactorial,
not just one single thing. So yes, you've got the
malicetia, yeast overgrowth or sensitivity.
Then there's an abnormal immune response in people who are
susceptible. Genetics probably plays a part.
Runs in families sometimes. Can do, And the activity of
(02:29):
those sebaceous glands is crucial too, because that's the
environment the yeast likes. So it's kind of a mix of things
coming together. Exactly.
Your body mounts this inflammatory response to the
yeast in those oily areas, and that's what leads to the skin
changes we see. It seems like some people's
immune systems just overreact tothis really common yeast.
(02:50):
What about things that make it worse, like triggers?
Yeah, definitely. Things can aggravate it.
Stuff like being I'll stress is a big one.
Fatigue. Stress.
Always stress. Tell me about it.
Seasonal changes too, often, worse in winter.
Having a weakened immune system for any reason, even some
medications, can trigger it. And we also see it more often
(03:12):
and sometimes more severely in people with certain neurological
conditions. Parkinson's disease is the
classic example. And Parkinson's, well, the
thinking is that immobility might contribute to sebum sort
of building up, making it a better environment for the
yeast. Interesting.
And dandruff? Where does that fit in?
Is it just mild sebroeic dermatitis?
(03:32):
Pretty much yeah. Dandruff or pitiosicopitis is
basically considered a non inflamed form just on the scalp.
You get the scaling but usually not that significant redness you
see in full blown sebroeic dermatitis.
So related, but less severe. Exactly right.
Who's more likely to get this then?
Are there specific risk factors we should know about?
(03:52):
Definitely. There are known risk factors.
So having a family history bumpsup your chances.
Makes sense having oily skin, which is logical given where it
pops up. Yeah.
And then certain medical conditions really increase the
risk. Yeah, we mentioned Parkinson's.
And HIV. Yes, HIV is a big one.
The rates are much, much higher in people with HIV.
Yeah. And it can be more severe, too.
Yeah, that's a really key association to remember.
(04:14):
OK, HIV, Parkinson's. What else?
Stress. Definitely a risk factor and a
trigger and generally having a weakened immune system from any
cause. In age you mentioned it starts
after puberty. Yeah, it has this interesting
pattern. It's really common in babies.
That's cradle cap. Then it can peak in adolescence,
and then there's another major peak in adults, typically
(04:35):
between 30 and 60 years old. Got it.
Infants, teens, and middle-aged adults.
That's the pattern. OK, let's dig a bit deeper into
the pathophysiology. What's actually happening sort
of under the skin? Right.
So it really comes down to that interaction we touched on.
He's got the malicids, the yeasts which live normally on
(04:55):
most people's skin. They feed on the oils, the sebum
produced by those sebaceous glands.
Now in someone who's susceptible, their immune system
seems to recognise bits of this yeast or stuff it produces and
kicks off an inflammatory response.
Like an overreaction, you said. Exactly like an exaggerated
response. And that inflammation is what
causes the skin cells to turn over faster, leading to the
(05:18):
scaling, and it also causes the redness and the itch.
And the link to HIV and Parkinson's, how does that fit
pathophysiologically? Well, it likely relates to how
those conditions affect either the immune system.
Like with HIV the immune regulation is off or maybe sebum
production or it's composition like potentially in Parkinson's.
(05:38):
It just makes individuals more prone to this inflammatory
reaction. OK, that makes sense.
So we've got this picture, red, greasy, scaly patches,
especially in those oily zones. But you know, lots of skin
conditions can look kind of likethat.
Absolutely. So for revision, knowing what
else it could be, the differentials, that's super
(05:59):
important, is it? Oh definitely, this is a key
area. While you know often you can
diagnose Sebra dermatitis just by looking, especially in a
typical case, you have to consider other possibilities,
especially for exams. So what are the main ones?
The big ones that can look similar are psoriasis, atopic
dermatitis that's eczema, contact dermatitis and various
fungal infections like ringworm.Right.
(06:21):
How do you start to tell them apart?
Thinking about the location is really helpful, just like you
would in clinic. OK, give us some examples, say
on the face. OK, on the face, besides
seborroic dermatitis, you might think about rosacea.
That usually involves redness and flushing, maybe some spots,
but typically doesn't have that prominent greasy scale.
Or even something like lupus, which can cause a facial rash,
(06:42):
though that's often more triggered by the sun.
And the scalp, that's a common spot.
Yeah, the scalp is key. Psoriasis is probably the number
one differential there, and sometimes they can even overlap,
which gets confusingly called C bump psoriasis.
How scalp psoriasis different? Typically psoriasis scales are
thicker, drier, and more silverywhite compared to the greasy,
often yellowish scales of Subderm.
(07:05):
Psoriasis also often affects theelbows, knees, lower back places
Subderm usually doesn't. OK, thicker silver scales.
Think psoriasis. What else on the scalp?
You'd also think about maybe infected eczema or teenicopedus.
That's fungal ringworm of the scalp, right?
And on the torso, chest and back.
Yeah, the list gets a bit longer.
There could be a topic, eczema, often drier and maybe different
(07:28):
spots like elbow creases could be contact dermatitis if it's
localised where something touch the skin.
OK, maybe pityriasis rosea, which has quite a distinct
Harold patch and Christmas tree pattern, Usually pityriasis
versicolor, another fungal thing, often causing pale or
dark patches on the back and chest like in simplex, which is
thickened itchy skin from chronic scratching or
(07:49):
Candidiasis, a yeast infection often in skin folds.
Wow, OK, that's quite a list forthe torso.
So the key is really looking closely at the type of scale and
the exact location. Exactly combine the location
those classic sebaceous gland areas like scalp, eyebrows,
nasolabial folds, chest with thequality of the rash.
Remember red bass? Greasy or yellowish scales?
(08:12):
That's your classic Subderm picture.
So let's try a mini vignette like for revision.
Say a 45 year old man comes in itchy scalp for months, greasy
yellowish scales, also got some redness and flaking around his
nose and in his eyebrows. Most likely diagnosis.
Bingo. Greasy yellow scales on the
scalp plus facial involvement inthose classic spots in as labial
fold eyebrows. That pattern shuts seborrheic
(08:33):
dermatitis. But if the vignette said thick
silvery scales on the scalp and patches on his elbows.
Then you'd be leaning much more towards psoriasis.
See how the details matter. Got it.
Greasy plus typical location. Likely Subderm.
OK, let's talk numbers. How common is this globally?
UK. It's really pretty common.
Generally, sources say it affects somewhere between maybe
(08:55):
1 to 5% of the global population.
Some figures put it around 2% overall.
OK. But as we keep saying, the big
headline in epidemiology is thathuge difference in people who
are immunocompromised. Right, the HIV link.
Exactly. And people with HIV, the
prevalence just rockets up figures like 34% to even over
80% are quoted, and it tends to be more widespread and severe,
(09:17):
especially with advanced HIV or AIDS.
That's a critical link. Any difference between men and
women? Yes, generally it's more common
in males. Why is that?
The thinking is it might be linked to male hormones,
androgens, influencing the sebaceous glands to produce more
oil, creating that favourable environment.
OK. And just to recap those age
peaks again. Yep.
Infant's cradle cap, then adolescence, and then that big
(09:39):
adult peak, usually 30s to 60s. Right.
We've touched on the general look, but let's get really
specific about the clinical features.
How does it present in those different areas?
OK, let's break it down again. Always thinking red base, greasy
yellowish scale. Location is everything on the
face. Classic spots are the nozolabial
(10:01):
cake folds, those lines from nose to mouth, over the bridge
of the nose, in the eyebrows, the central forehead, even the
eyelashes. That's called cibroic
blepharitis. It looks like inflamed, maybe
slightly greasy patches with fine scales.
And the scalp. Scalp is probably the most
common sight. It can range from just simple
dandruffine, white scaling to more obvious I'll defined.
(10:23):
Pink patches with thicker yellowish or white scale can
affect just part of the scalp orthe whole thing.
Itch is really common. Here, Yeah, itchy scalp sounds
miserable. What about chest and back?
On the chest and upper back you might see small sort of reddish
brown bumps with greasy scales off and around hair follicles.
Or you can get larger, more defined patches.
The area right over the sternum,the breastbone is a really
(10:44):
classic spot. OK, sternum, good tip and
flexures like armpits. Yeah, the in the Fletcher's
armpits, groyne area, under the breasts, sometimes behind the
ears. It tends to present as just red
patches, maybe some bumps or plaques because it's in a fold,
might look a bit moist and can sometimes resemble interfrigo,
which is just irritation from skin rubbing on skin.
(11:05):
So the appearance can vary a bitdepending on the location, but
that greasy scale and redness and oily areas is the theme.
Exactly. Now, how do doctors actually
diagnose this? Do you need lots of tests?
Well, good news here. For exams and practise,
diagnosis is usually pretty straightforward.
Most of the time it's a clinicaldiagnosis.
Meaning you just look at it. Take a history.
(11:27):
Yep. Based on the characteristic
appearance that rash we described and where it is on the
body, plus the patient's story, the itch, any triggers they've
noticed if it comes and goes. So usually no blood tests or
biopsies needed. Not routinely, no.
Specific investigations aren't typically required if the
pitcher looks typical. When might you do a test then?
(11:47):
Really only if the diagnosis is uncertain or if you're actively
trying to rule out one of those differentials we talked about.
Like the fungal? Infection.
Exactly, If you suspect teeny capitis on the scalp or maybe
Peter Isis versicolor on the chest, you might do a skin
scraping. You scrape off a few scales,
send them for microscopy and culture to look for fungus.
And a biopsy. Very rarely, maybe if it looks
(12:09):
really unusual or isn't responding to standard
treatments and you're still scratching your head about the
diagnosis after considering the common stuff.
OK. So mostly clinical diagnosis,
once it is diagnosed, how do we treat it?
What are the main goals right the.
Goals are pretty clear. We want to one, control the
symptoms like the itch and scaling, 2.
Reduce the inflammation and redness and three, basically
(12:31):
clear up the rash during those flare ups.
And topical treatment stuff you put directly on the skin are
absolutely the mainstay. Creams, shampoos, lotions.
What kinds of ingredients are inthese topicals?
2 main types. First, topical antifungals.
Things like ketoconazole or cyclopyrox.
These target that malicets the yeast.
OK, tackling the yeast. And 2nd topical corticosteroids.
(12:54):
These are anti inflammatories. They calm down the redness and
the itch. Usually used just for short
periods during a flare. What about specifically for the
scalp? Any particular approach?
Yeah, there's often a stepwise approach recommended, like in
the nice CKS guidance. You might start with over the
counter shampoos containing things like zinc pyridione.
Like head and shoulders. Exactly, or Coltar shampoos.
(13:17):
If those aren't cutting it then you step up to medicated
shampoos like ketoconazole shampoo may be used a couple of
times a week. Selenium sulphide shampoo is
another option, and you can alsoget topical steroid lotions or
gels specifically for the scalp if the inflammation is bad.
OK. And for the face and body,
similar idea. Similar principle, yeah, topical
antifungal creams like ketoconazole cream and again,
(13:39):
topical steroids, but usually milder ones on the face.
Use sparingly and for short bursts to manage flares.
You mentioned it's chronic so flares are common.
How do you manage that long term?
That's the challenge. Because recurrences are so
common, treatment often involvesnot just treating flares when
they happen, but sometimes usingtreatments regularly to prevent
them. Like maintenance therapy?
(14:00):
Exactly. Yeah, maybe using an antifungal
shampoo once or twice a week, even when the scalp is clear, or
intermittent use of the topical steroid if needed.
The combination of regular antifungal use with intermittent
steroids is a common strategy. Any other options?
Yeah, another class of topicals sometimes used, especially on
the face where you want to avoidtoo much steroid, are
(14:22):
calcineurin inhibitors, things like tacrolimus or PIE
macrolimus. They also reduce inflammation,
but work differently from steroids.
They're increasingly seen as a good alternative or addition.
OK, what if it's really severe, like widespread or just not
responding to topicals? For those more severe or
resistant cases, you might have to consider systemic treatments
(14:42):
pills. Oral antifungals like
ketoconazole tablets can be used.
Sometimes oral antibiotics like tetracyclines are used not
really for infection but for their anti-inflammatory effects.
And then in really difficult rare cases, things like oral
isocretinoline, you know, the strong acne drug or even
ultraviolet light therapy might be considered.
But these are definitely specialist treatments.
(15:03):
And you mentioned that link again if it's severe or
atypical. Yes, absolutely.
Crucial point, especially for exams.
Severe, widespread or atypical cibroic dermatitis.
You must consider testing for underlying HIV infection.
That association is just so strong.
Got it. OK.
Moving towards the long term outlook, what's the prognosis
(15:25):
generally like? Well, like we said right at the
start, it is a chronic condition, so unfortunately
doesn't typically just vanish forever on its own.
So no cure. No complete cure.
As such, what people can expect is a course that waxes and
wanes, periods where it flares up, the rash is active, and
periods of remission where it clears up or is much quieter.
But it is manageable. Yes, that's the good news.
(15:45):
While there's no cure, it usually responds well to the
treatments we've discussed. Effective symptom management is
definitely achievable for most people, but you have to
anticipate those relapses. They're just part of the deal.
Managing expectations is important, OK.
And does it lead to any serious complications, usually anything
dangerous? Generally speaking, no.
(16:08):
The sources usually say there aren't typically serious
physical health complications directly from the subderm
itself. But it can affect quality of
life. Oh absolutely, the itch can be
really bothersome sometimes, burning sensations, and because
it's often visible face scalps, it can definitely have a
significant impact on quality oflife, cause emotional distress,
(16:29):
affect self esteem. We shouldn't underestimate that.
Any risk of infection? Yes, there's a risk of secondary
bacterial or fungal infection developing on the inflamed skin,
especially if it gets scratched a lot and the skin barrier is
broken. And then very rarely in really
severe cases, again often linkedto things like immunosuppression
or maybe severe heart failure, it could potentially progress to
(16:50):
cover most of the body surface with redness and scaling.
That's called generalised sybaric erythroderma, but that's
quite uncommon. Wow, OK, that was a really
comprehensive run through of adult Saberac dermatitis.
We've covered well everything from the potential causes that
malicets ease the immune response to what it actually
looks like, those greasy scales and specific spots.
(17:13):
Yeah, and how to tell it apart from other things like
psoriasis, which is key. Definitely.
And the management that stepwiseapproach focusing on topicals
first. Absolutely understanding those
core features, greasy scale location, malacetzia link, those
HIV Parkinson's associations. That's gold dust for recall,
especially in an exam. And I think knowing it's chronic
(17:33):
but manageable, that treatment is about controlling flares,
maybe some maintenance. That's a really important take
home message. Totally agree, and remembering
diagnosis is usually clinical. That saves unnecessary tests.
It's common, so you'll definitely see it being
comfortable recognising it and knowing those first steps is
super useful. So what does this all boil down
(17:54):
to for you? Listening.
Hopefully a much clearer, more structured picture of adult
seborrheic dermatitis. Remember the key takeaways,
greasy scales, those typical locations, scalp, face, chest,
the malesedia connection and think about those associated
conditions like HIV and Parkinson's, especially in
severe cases. And keep those main
(18:14):
differentials, especially psoriasis in the back of your
mind when you see a scaly scalp.Knowing the typical treatments,
antifungals, short term steroidsand that clinical diagnosis
rule, those are really high yield points.
OK, a final thought to leave youwith then.
Given how closely this seems tied to malicidia, yeast and the
individual's immune reaction, what might future research look
like? Could we see maybe more targeted
(18:36):
treatments, perhaps something that deals with the use more
specifically? Or fine tunes just that bit of
the immune response without knocking the whole system?
Something to think about. For more free MSRA revision
resources, do visit freem-sra.com and IF if you're
looking for the full premium Revision toolkit, head over to
athmsracom.
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